So say if someone is using a nail file would you be offended ? What about whashing hands ? Realy something that does not smell or make noise , what's the problem ? Look away and stop projecting your own programming on other people.
My problem is when people cut their nails in the office let them fly all over the place without cleaning them up. That's the image that came to mind in the parent's comment and it grossed me out.
Essentially, if whatever you're doing involves leaving visible bits of you behind (e.g. nail cutting) please do it at home or in the bathroom at work.